1. Field of Invention
This invention relates to writing instruments.
2. Description of Prior Art
There are many patents on writing instruments. However, these instruments generally have common features including a marking substance (e.g. ink, graphite), a rigid shaft to contain and enable a user to guide and deposit the marking substance onto an object. Also, most writing instruments have a means of capping or retracting the marking substance such that it does not write on unintended surfaces (e.g. Des. Patent 409,658 to Chevaller et al. and U.S. Pat. No. 5,601,376 to Badr et al.)
For the purpose of user comfort, the shaft is typically around six inches in length such that one end can be supported by a combination of fingers and the other end supported on the base of the hand between the thumb and first finger. A writing instrument much shorter than the standard length is not long enough to be supported by the base of the hand. Grasping with the fingers alone, it is difficult, awkward, and tiring to control the instrument, making it generally an unacceptable design.
However, the standard-length writing instrument has a fundamental problem in that it is generally too long and too rigid for easy storage on a person. Often the most convenient storage area on a person is a clothes pocket. But, the standard shirt pocket is smaller in both dimensions that a standard writing instrument, causing it to protrude from the pocket. For fashion and practical reasons (it can fall out or snag things), most users do not want a writing instrument protruding from their shirt pocket.
Pants pockets are generally long enough to hold the entire length of a standard instrument, but the instrument can cause discomfort and damage when the user sits down with the instrument in the pocket. For the same reasons, a standard length instrument is too long and rigid to fit inside a man's wallet, small notebook, electronic devices such as calculators and personnel digital assistants (PDAs), and some women purses.
Therefore, a writing instrument is needed that is standard length during use but can be made much shorter and smaller for storage. Folding is one means of making a pin long for operation but shorter during storage (for example, U.S. Pat. No. 4,149,812 to Huffman, Jr and U.S. Pat. No. 5,988,918 to Johnson). However, a folding instrument as described by Huffman does not reduce its volume only its length, and the user is not fully protect against inadvertent marking in its closed configuration. The folding instrument described by Johnson does not reduce volume either and is awkward and impractical to fold into a shorter length.